rtlwifi: rtl8192cu: Fix too long disable of IRQs

rtlwifi: rtl8192cu: Fix too long disable of IRQs

commit a53268be0cb9763f11da4f6fe3fb924cbe3a7d4a upstream.

In commit f78bccd79ba3cd9d9664981b501d57bdb81ab8a4 entitled "rtlwifi:
rtl8192ce: Fix too long disable of IRQs", Olivier Langlois
<olivier@trillion01.com> fixed a problem caused by an extra long disabling
of interrupts. This patch makes the same fix for rtl8192cu.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>